   **Bonus**: Change your mocking to use =1x=> arrows for `sum-sq` to return different, but predictable, values for
   each call.
 
+  Solutions are in `exercises-solutions-spec`.
+
   ## Using the original function (Spying)
 
   If you want to spy on a function, you can use mocking with a pre-capture of the function:

  that tests if `2 * 2 = 4`. Remember to update `tests-to-run`. You can use the `ns` preamble from `sample-spec` to
  get the various requires correct.

  ## Assertions

  Special arrows:


  Create an additonal spec (in the same file as before) that uses the `=fn=>` arrow to check that an expression results
  in an even value.

  Solutions are in `exercises-solutions-spec`.

  ## Mocking

